On the temporal diversity of knowledge in science

Understanding the diversity of scientific knowledge is pivotal for elucidating trends in science and innovation. While interdisciplinarity and team diversity have been extensively studied, the temporal diversity of knowledge remains underexplored. This paper introduces a novel framework for assessing temporal diversity in scholarly research. Analyzing 31 million articles from the past seven decades, I revealed an increasing trend in temporal diversity, reflecting the cumulative nature of scientific knowledge. Additionally, I found that temporal diversity is negatively associated with citation impact but positively associated with disruption. These patterns are robust and consistent across different contexts. Moreover, the findings suggest that higher temporal diversity leading to greater disruption may be primarily due to the use of older references. However, the disadvantages of temporal diversity in terms of citation impact cannot be entirely explained by other factors. Collectively, this study elucidates the dynamics of temporal diversity and its implications for innovation, providing new frameworks in the science of science and evidence on how innovation is driven by the temporal diversity of knowledge.